Synthesis of monodispersed VO₂@Au core–semishell submicroparticles and their switchable optical properties

Monodispersed VO₂ core/Au semishell submicroparticles have been synthesized and optically characterized. Compared to standard noble metal particles, these VO₂@Au core–semishell structures exhibit additional reversible and tunable localized surface plasmon resonance (LSPR) under external temperature modulation. The LSPR peak shifts from 755 nm to 546 nm when the temperature changes from 25 °C to 90 °C. Such a large and reversible shift (more than 200 nanometers in wavelength) can be attributed to the unique semiconductor–metal transition (SMT) of the VO₂ material.